U.S. patent number 10,463,505 [Application Number 15/235,053] was granted by the patent office on 2019-11-05 for bone preparation apparatus and method.
The grantee listed for this patent is Kambiz Behzadi. Invention is credited to Kambiz Behzadi.
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United States Patent |
10,463,505 |
Behzadi |
November 5, 2019 |
Bone preparation apparatus and method
Abstract
A system and method for improving installation of a prosthesis.
Devices include prosthesis installation tools, prosthesis assembly
tools, site preparation systems, and improved power tools used in
implant site preparation.
Inventors: |
Behzadi; Kambiz (Pleasanton,
CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Behzadi; Kambiz |
Pleasanton |
CA |
US |
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Family
ID: |
59274904 |
Appl.
No.: |
15/235,053 |
Filed: |
August 11, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170196705 A1 |
Jul 13, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15202434 |
Jul 5, 2016 |
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62277294 |
Jan 11, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B
17/142 (20161101); A61B 17/1666 (20130101); A61B
17/320068 (20130101); A61F 2/4603 (20130101); A61F
2/4607 (20130101); A61F 2/4609 (20130101); A61F
2/4612 (20130101); A61F 2002/4627 (20130101); A61F
2002/4681 (20130101); A61F 2002/4683 (20130101) |
Current International
Class: |
A61F
2/46 (20060101); A61B 17/32 (20060101); A61B
17/16 (20060101); A61B 17/14 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1433445 |
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Jun 2004 |
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EP |
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2018031752 |
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Feb 2018 |
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WO |
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Other References
International Search Report for International application No.
PCT/US2017/046261, dated Oct. 18, 2017. cited by applicant .
Written Opinion of the International Searching Authority for
International application No. PCT/US2017/046261, dated Oct. 18,
2017. cited by applicant .
International Search Report for International application No.
PCT/US2017/012753, dated May 5, 2017. cited by applicant .
Written Opinion of the International Searching Authority for
International application No. PCT/US2017/012753 dated May 5, 2017.
cited by applicant .
U.S. Appl. No. 16/276,639, filed Feb. 15, 2019, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 16/278,085, filed Feb. 16, 2019, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 16/278,668, filed Feb. 18, 2019, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 16/374,750, filed Apr. 4, 2019, Kambiz Behzadi et
al. cited by applicant .
U.S. Appl. No. 16/375,736, filed Apr. 4, 2019, Kambiz Behzadi et
al. cited by applicant .
U.S. Appl. No. 62/277,294, filed Jan. 11, 2016, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 62/353,024, filed Jun. 21, 2016, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 62/355,657, filed Jun. 28, 2016, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 62/373,515, filed Aug. 11, 2016, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 62/651,077, filed Mar. 31, 2018, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 62/742,851, filed Oct. 8, 2018, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 62/743,042, filed Oct. 9, 2018 Kambiz Behzadi et al.
cited by applicant .
U.S. Appl. No. 15/202,434, filed Jul. 5, 2016, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 15/234,782, filed Aug. 11, 2016, Kambiz Behzadi et
al. cited by applicant .
U.S. Appl. No. 15/234,880, filed Aug. 11, 2016, Kambiz Behzadi et
al. cited by applicant .
U.S. Appl. No. 15/235,032, filed Aug. 11, 2016, Kambiz Behzadi et
al. cited by applicant .
U.S. Appl. No. 15/284,091, filed Oct. 3, 2016, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 15/362,675, filed Nov. 28, 2016, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 15/396,785, filed Jan. 2, 2017, Kambiz Behzadi et
al. cited by applicant .
U.S. Appl. No. 15/398,996, filed Jan. 5, 2017, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 15/453,219, filed Mar. 8, 2017, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 15/592,229, filed May 11, 2017, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 15/687,324, filed Aug. 25, 2017, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 15/716,529, filed Sep. 27, 2017, Kambiz Behzadi et
al. cited by applicant .
U.S. Appl. No. 15/716,533, filed Sep. 27, 2017, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 16/030,603, filed Jul. 9, 2018. Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 16/030,824, filed Jul. 9, 2018, Kambiz Behzadi.
cited by applicant .
U.S. Appl. No. 16/154,033, filed Oct. 8, 2018, Kambiz Behzadi et
al. cited by applicant.
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Primary Examiner: Beccia; Christopher J
Attorney, Agent or Firm: Patent Law Offices of Michael E.
Woods Woods; Michael E.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent
application Ser. No. 15/202,434 which claims benefit of U.S. Patent
Application No. 62/277,294, these applications are hereby expressly
incorporated by reference in their entireties for all purposes.
Claims
What is claimed as new and desired to be protected by Letters
Patent of the United States is:
1. A device for imparting a vibratory bone preparation force,
comprising: a rod having a shaft including a proximal end, a distal
end spaced apart from said distal end, and a longitudinal axis
extending from said proximal end to said distal end through said
rod; a motor producing a periodic motion; a driver system, coupled
to said proximal end and to said motor, producing a driven
vibratory rod motion for said distal end from said period motion;
an attachment system coupled to said distal end, said attachment
system configured to engage an attachment structure; and a set
attachments, each particular attachment from said set of
attachments including said attachment structure; wherein said
driven vibratory rod motion includes a selectable vibratory mode
chosen from a vibratory mode group including a bidirectionally
driven vibratory mode having a first driven vibratory direction and
a second driven vibratory direction.
2. The device of claim 1 wherein said vibratory mode group further
includes a first unidirectional vibratory mode and further
comprising a vibratory mode selector to select a particular one
vibratory mode from said bidirectionally driven vibratory mode and
said first unidirectional vibratory mode.
3. The device of claim 1 wherein said bidirectionally driven
vibratory mode includes a bidirectional longitudinal motion
vibratory mode.
4. The device of claim 3 wherein said vibratory mode group further
includes a first unidirectional longitudinal vibratory mode and
further comprising a vibratory mode selector to select a particular
one vibratory mode from said bidirectional longitudinal motion
vibratory mode and said first unidirectional longitudinal vibratory
mode.
5. The device of claim 1 wherein said bidirectionally driven
vibratory mode includes a bidirectional rotational motion vibratory
mode.
6. The device of claim 5 wherein said vibratory mode group further
includes a first unidirectional rotational vibratory mode and
further comprising a vibratory mode selector to select a particular
one vibratory mode from said bidirectional rotational vibratory
mode and said first unidirectional rotational vibratory mode.
7. The device of claim 1 wherein said set of attachments includes a
bone broach.
8. The device of claim 1 wherein said set of attachments includes a
set of broaches including a range of varying sizes and wherein said
range of varying sizes include 1/2 millimeter variations.
9. The device of claim 5 wherein said set of attachments includes a
bone broach.
10. The device of claim 9 wherein said set of attachments includes
a set of broaches including a range of varying sizes and wherein
said range of varying sizes include 1/2 millimeter variations.
11. The device of claim 1 wherein said set of attachments includes
an acetabular broach.
12. The device of claim 3 wherein said set of attachments includes
an acetabular broach.
13. The device of claim 1 wherein said bidirectionally driven
vibratory mode operates at an ultrasonic frequency.
14. The device of claim 9 wherein said bidirectionally driven
vibratory mode operates at an ultrasonic frequency.
15. The device of claim 11 wherein said bidirectionally driven
vibratory mode operates at an ultrasonic frequency.
Description
FIELD OF THE INVENTION
The present invention relates generally to installation of a
prosthesis, and more specifically, but not exclusively, to
improvements in prosthesis placement and positioning.
BACKGROUND OF THE INVENTION
The subject matter discussed in the background section should not
be assumed to be prior art merely as a result of its mention in the
background section. Similarly, a problem mentioned in the
background section or associated with the subject matter of the
background section should not be assumed to have been previously
recognized in the prior art. The subject matter in the background
section merely represents different approaches, which in and of
themselves may also be inventions.
Earlier patents issued to the present applicant have described
problems associated with prosthesis installation, for example
acetabular cup placement in total hip replacement surgery. See U.S.
Pat. Nos. 9,168,154 and 9,220,612, which are hereby expressly
incorporated by reference thereto in their entireties for all
purposes. Even though hip replacement surgery has been one of the
most successful operations, it continues to be plagued with a
problem of inconsistent acetabular cup placement. Cup
mal-positioning is the single greatest cause of hip instability, a
major factor in polyethylene wear, osteolysis, impingement,
component loosening and the need for hip revision surgery.
These incorporated patents explain that the process of cup
implantation with a mallet is highly unreliable and a significant
cause of this inconsistency. The patents note two specific problems
associated with the use of the mallet. First is the fact that the
surgeon is unable to consistently hit on the center point of the
impaction plate, which causes undesirable torques and moment arms,
leading to mal-alignment of the cup. Second, is the fact that the
amount of force utilized in this process is non-standardized.
In these patents there is presented a new apparatus and method of
cup insertion which uses an oscillatory motion to insert the
prosthesis. Prototypes have been developed and continue to be
refined, and illustrate that vibratory force may allow insertion of
the prosthesis with less force, as well, in some embodiments, of
allowing simultaneous positioning and alignment of the implant.
There are other ways of breaking down of the large undesirable,
torque-producing forces associated with the discrete blows of the
mallet into a series of smaller, axially aligned controlled taps,
which may achieve the same result incrementally, and in a stepwise
fashion to those set forth in the incorporated patents, (with
regard to, for example, cup insertion without unintended
divergence).
There are two problems that may be considered independently, though
some solutions may address both in a single solution. These
problems include i) undesirable and unpredictable torques and
moment arms that are related to the primitive method currently used
by surgeons, which involves manually banging the mallet on an
impaction plate mated to the prosthesis and ii) non-standardized
and essentially uncontrolled and unquantized amounts of force
utilized in these processes.
What is needed is a system and method for improving installation of
a prosthesis.
BRIEF SUMMARY OF THE INVENTION
Disclosed is a system and method for improving installation of a
prosthesis. The following summary of the invention is provided to
facilitate an understanding of some of the technical features
related to prosthesis assembly and installation, and is not
intended to be a full description of the present invention. A full
appreciation of the various aspects of the invention can be gained
by taking the entire specification, claims, drawings, and abstract
as a whole. The present invention is applicable to other prosthesis
in addition to acetabular cups, other modular prosthesis in
addition to assembly of modular femoral and humeral prosthesis, and
to other alignment and navigation systems in addition to referenced
light guides.
An embodiment of the present invention may include axial alignment
of force transference, such as, for example, an axially sliding
hammer moving between stops to impart a non-torqueing installation
force. There are various ways of motivating and controlling the
sliding hammer, including a magnitude of transferred force.
Optional enhancements may include pressure and/or sound sensors for
gauging when a desired depth of implantation has occurred.
Other embodiments include adaptation of various devices for
accurate assembly of modular prostheses, such as those that include
a head accurately impacted onto a trunion taper that is part of a
stem or other element of the prosthesis.
Still other embodiments include an alignment system to improve site
preparation, such as, for example, including a projected visual
reference of a desired orientation of a tool and then having that
reference marked and available for use during operation of the tool
to ensure that the alignment remains proper throughout its use,
such as during a reaming operation.
Further embodiments include enhancement of various tools, such as
those used for cutting, trimming, drilling, and the like, with
ultrasonic enhancement to make the device a better cutting,
trimming, drilling, etc. device to enable its use with less
strength and with improved accuracy.
Embodiments disclosed herein may include selective operational
directionality. That is, for a BMD that includes vibration, it may
be advantageous to control whether that vibration is driven
unidirectionally and/or bidirectionally. For example, for an
installation tool that installs a prosthesis into bone, it may be
advantageous when a net vibratory motion is driven towards the
installation site (moves toward installation) and not driven away
from the installation (moves toward extraction). In a revision
tool, such as disclosed in U.S. patent application Ser. No.
15/092,384, which is hereby expressly incorporated by reference in
its entirety for all purposes, where it may be desired to remove a
previously installed prosthesis, reversing the drive direction of
the unidirectional operation helps to remove the prosthesis by
providing net extractive forces on the prosthesis to be removed. As
further described herein, in some implementations, it may be
desirable to drive a tool operated by the BMD with a bidirectional
motion. Such a system may be used with a new acetabular broach,
particularly with bidirectional vibratory motion.
Any of the embodiments described herein may be used alone or
together with one another in any combination. Inventions
encompassed within this specification may also include embodiments
that are only partially mentioned or alluded to or are not
mentioned or alluded to at all in this brief summary or in the
abstract. Although various embodiments of the invention may have
been motivated by various deficiencies with the prior art, which
may be discussed or alluded to in one or more places in the
specification, the embodiments of the invention do not necessarily
address any of these deficiencies. In other words, different
embodiments of the invention may address different deficiencies
that may be discussed in the specification. Some embodiments may
only partially address some deficiencies or just one deficiency
that may be discussed in the specification, and some embodiments
may not address any of these deficiencies.
Other features, benefits, and advantages of the present invention
will be apparent upon a review of the present disclosure, including
the specification, drawings, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying figures, in which like reference numerals refer to
identical or functionally-similar elements throughout the separate
views and which are incorporated in and form a part of the
specification, further illustrate the present invention and,
together with the detailed description of the invention, serve to
explain the principles of the present invention.
FIG. 1-FIG. 6 illustrate embodiments including installation of a
prosthesis, including installation into living bone;
FIG. 1 illustrates an embodiment of the present invention for a
sliding impact device;
FIG. 2 illustrates a lengthwise cross-section of the embodiment
illustrated in FIG. 1 including an attachment of a navigation
device;
FIG. 3 illustrates a cockup mechanical gun embodiment, an
alternative embodiment to the sliding impact device illustrated in
FIG. 1 and FIG. 2;
FIG. 4 illustrates an alternative embodiment to the devices of FIG.
1-3 including a robotic structure;
FIG. 5 illustrates an alternative embodiment to the devices of FIG.
1-4 including a pressure sensor to provide feedback;
FIG. 6 illustrates an alternative embodiment to the feedback system
of FIG. 5 including a sound sensor to provide feedback for the
embodiments of FIG. 1-5;
FIG. 7-FIG. 10 illustrate prosthesis assembly embodiments including
use of variations of the prosthesis installation embodiments of
FIG. 1-FIG. 6, such as may be used to reduce a risk of
trunionosis;
FIG. 7 illustrates a modular prosthesis and assembly tools;
FIG. 8 illustrates a femoral head to be assembled onto a trunion
attached to a femoral stem;
FIG. 9 illustrates alignment of an installation device with the
femoral head for properly aligned impaction onto the trunion, such
as an embodiment of FIG. 1-FIG. 6 adapted for this application;
FIG. 10 illustrates use of a modified vibratory system for assembly
of the modular prosthesis;
FIG. 11-FIG. 12 illustrate an improvement to site preparation for
an installation of a prosthesis;
FIG. 11 illustrates an environment in which a prosthesis is
installed highlighting problem with site preparation; and
FIG. 12 illustrates an alignment system for preparation and
installation of a prosthesis;
FIG. 13 illustrates modified surgical devices incorporating
vibratory energy as at least an aid to mechanical preparation;
FIG. 14 illustrates a BMD having bidirectional longitudinal motion;
and
FIG. 15 illustrates a BMD having bidirectional rotational
motion.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention provide a system and method
for improving installation of a prosthesis. The following
description is presented to enable one of ordinary skill in the art
to make and use the invention and is provided in the context of a
patent application and its requirements.
Various modifications to the preferred embodiment and the generic
principles and features described herein will be readily apparent
to those skilled in the art. Thus, the present invention is not
intended to be limited to the embodiment shown but is to be
accorded the widest scope consistent with the principles and
features described herein.
Definitions
Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
general inventive concept belongs. It will be further understood
that terms, such as those defined in commonly used dictionaries,
should be interpreted as having a meaning that is consistent with
their meaning in the context of the relevant art and the present
disclosure, and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
The following definitions apply to some of the aspects described
with respect to some embodiments of the invention. These
definitions may likewise be expanded upon herein.
As used herein, the term "or" includes "and/or" and the term
"and/or" includes any and all combinations of one or more of the
associated listed items. Expressions such as "at least one of,"
when preceding a list of elements, modify the entire list of
elements and do not modify the individual elements of the list.
As used herein, the singular terms "a," "an," and "the" include
plural referents unless the context clearly dictates otherwise.
Thus, for example, reference to an object can include multiple
objects unless the context clearly dictates otherwise.
Also, as used in the description herein and throughout the claims
that follow, the meaning of "in" includes "in" and "on" unless the
context clearly dictates otherwise. It will be understood that when
an element is referred to as being "on" another element, it can be
directly on the other element or intervening elements may be
present therebetween. In contrast, when an element is referred to
as being "directly on" another element, there are no intervening
elements present.
As used herein, the term "set" refers to a collection of one or
more objects. Thus, for example, a set of objects can include a
single object or multiple objects. Objects of a set also can be
referred to as members of the set. Objects of a set can be the same
or different. In some instances, objects of a set can share one or
more common properties.
As used herein, the term "adjacent" refers to being near or
adjoining. Adjacent objects can be spaced apart from one another or
can be in actual or direct contact with one another. In some
instances, adjacent objects can be coupled to one another or can be
formed integrally with one another.
As used herein, the terms "connect," "connected," and "connecting"
refer to a direct attachment or link. Connected objects have no or
no substantial intermediary object or set of objects, as the
context indicates.
As used herein, the terms "couple," "coupled," and "coupling" refer
to an operational connection or linking. Coupled objects can be
directly connected to one another or can be indirectly connected to
one another, such as via an intermediary set of objects.
The use of the term "about" applies to all numeric values, whether
or not explicitly indicated. This term generally refers to a range
of numbers that one of ordinary skill in the art would consider as
a reasonable amount of deviation to the recited numeric values
(i.e., having the equivalent function or result). For example, this
term can be construed as including a deviation of .+-.10 percent of
the given numeric value provided such a deviation does not alter
the end function or result of the value. Therefore, a value of
about 1% can be construed to be a range from 0.9% to 1.1%.
As used herein, the terms "substantially" and "substantial" refer
to a considerable degree or extent. When used in conjunction with
an event or circumstance, the terms can refer to instances in which
the event or circumstance occurs precisely as well as instances in
which the event or circumstance occurs to a close approximation,
such as accounting for typical tolerance levels or variability of
the embodiments described herein.
As used herein, the terms "optional" and "optionally" mean that the
subsequently described event or circumstance may or may not occur
and that the description includes instances where the event or
circumstance occurs and instances in which it does not.
As used herein, the term "size" refers to a characteristic
dimension of an object. Thus, for example, a size of an object that
is spherical can refer to a diameter of the object. In the case of
an object that is non-spherical, a size of the non-spherical object
can refer to a diameter of a corresponding spherical object, where
the corresponding spherical object exhibits or has a particular set
of derivable or measurable properties that are substantially the
same as those of the non-spherical object. Thus, for example, a
size of a non-spherical object can refer to a diameter of a
corresponding spherical object that exhibits light scattering or
other properties that are substantially the same as those of the
non-spherical object. Alternatively, or in conjunction, a size of a
non-spherical object can refer to an average of various orthogonal
dimensions of the object. Thus, for example, a size of an object
that is a spheroidal can refer to an average of a major axis and a
minor axis of the object. When referring to a set of objects as
having a particular size, it is contemplated that the objects can
have a distribution of sizes around the particular size. Thus, as
used herein, a size of a set of objects can refer to a typical size
of a distribution of sizes, such as an average size, a median size,
or a peak size.
Embodiments of the present invention may include one of more
solutions to the above problems. The incorporated U.S. Pat. No.
9,168,154 includes a description of several embodiments, sometimes
referred to herein as a BMD3 device, some of which illustrate a
principle for breaking down large forces associated with the
discrete blows of a mallet into a series of small taps, which in
turn perform similarly in a stepwise fashion while being more
efficient and safer. The BMD3 device produces the same displacement
of the implant without the need for the large forces from the
repeated impacts from the mallet. The BMD3 device may allow
modulation of force required for cup insertion based on bone
density, cup geometry, and surface roughness. Further, a use of the
BMD3 device may result in the acetabulum experiencing less stress
and deformation and the implant may experience a significantly
smoother sinking pattern into the acetabulum during installation.
Some embodiments of the BMD3 device may provide a superior approach
to these problems, however, described herein are two problems that
can be approached separately and with more basic methods as an
alternative to, or in addition to, a BMD3 device. An issue of
undesirable torques and moment arms is primarily related to the
primitive method currently used by surgeons, which involves
manually banging the mallet on the impaction plate. The amount of
force utilized in this process is also non-standardized and
somewhat out of control.
With respect to the impaction plate and undesirable torques, an
embodiment of the present invention may include a simple mechanical
solution as an alternative to some BMD3 devices, which can be
utilized by the surgeon's hand or by a robotic machine. A direction
of the impact may be directed or focused by any number of standard
techniques (e.g., A-frame, C-arm or navigation system). Elsewhere
described herein is a refinement of this process by considering
directionality in the reaming process, in contrast to only
considering it just prior to impaction. First, we propose to
eliminate the undesirable torques by delivering the impacts by a
sledgehammer device or a structure (e.g., hollow cylindrical mass)
that travels over a stainless rod.
FIG. 1 illustrates an embodiment of the present invention for a
sliding impact device 100, and FIG. 2 illustrates a lengthwise
cross-section of sliding impact device 100 including an attachment
of a navigation device 205.
Device 100 includes a moveable hammer 105 sliding axially and
freely along a rod 110. Rod 110 includes a proximal stop 115 and
distal stop 120. These stops that may be integrated into rod 110 to
allow transference of force to rod 110 when hammer 105 strikes
distal stop 120. At a distal end 210 of rod 110, device 100
includes an attachment system 215 for a prosthesis 220. For
example, when prosthesis 220 includes an acetabular cup having a
threaded cavity 225, attachment system 215 may include a
complementary threaded structure that screws into threaded cavity
225. The illustrated design of device 100 allows only a perfect
axial force to be imparted. The surgeon cannot deliver a blow to
the edge of an impaction plate. Therefore the design of this
instrument is in and of itself protective, eliminating a problem of
"surgeon's mallet hitting on the edge of the impaction plate" or
other mis-aligned force transference, and creating undesirable
torques, and hence unintentional mal-alignment of prosthesis 220
from an intended position/orientation.
A longitudinal axis 230 extends through the ends of rod 110.
Attachment system 215 aligns prosthesis 220 to axis 230 when rod
110 is coupled to threaded cavity 225. An apex of prosthesis 220
(when it generally defines a hollow semispherical shell) supports a
structure that defines threaded cavity 225 and that structure may
define a plane 235 that may be tangent to the apex, with plane 235
about perpendicular to axis 230 when rod 110 engages prosthesis
220. Operation of device 100 is designed to deliver only axial
(e.g., aligned with axis 230 and thus non-torqueing) forces to
prosthesis 220. Other embodiments illustrated in FIG. 3-FIG. 6 may
be similarly configured.
FIG. 3 illustrates a cockup mechanical gun 300 embodiment, an
alternative embodiment to the sliding impact device illustrated in
FIG. 1 and FIG. 2. An alternate embodiment includes cockup
mechanical gun 300 that uses the potential energy of a cocked up
spring 305 to create an axially aligned impaction force. Hammer 105
is drawn back and spring 305 is locked until an operator actuates a
trigger 310 to release spring 305 and drive hammer 105 along rod
110 to strike distal stop 120 and transfer an axially aligned
impacting force to prosthesis 220.
Each pull of trigger 310 creates the same predetermined fixed unit
of force (some alternatives may provide a variably predetermined
force). The surgeon cannot deliver a misaligning impact to an
impaction plate with this design.
FIG. 4 illustrates an alternative robotic device 400 embodiment to
the devices of FIG. 1-3 including a robotic control structure 405.
For example, device 100 and/or device 300 may be mounted with robot
control structure 405 and the co-axial impacts may be delivered
mechanically by a robotic tool using pneumatic or electric
energy.
FIG. 5 illustrates an alternative embodiment 500 to the devices of
FIG. 1-4 including a pressure sensor 505 to provide feedback during
installation. With respect to management of the force required for
some of these tasks, it is noted that with current techniques (the
use of the mallet) the surgeon has no indication of how much force
is being imparted onto the implant and/or the implant site (e.g.,
the pelvis). Laboratory tests may be done to estimate what range of
force should be utilized in certain age groups (as a rough guide)
and then fashioning a device 500, for example a modified
sledgehammer 100 or cockup gun 300 to produce just the right amount
of force. Typically the surgeon may use up to 2000 N to 3000 N of
force to impact a cup into the acetabular cavity. Also, since some
embodiments cannot deliver the force in an incremental fashion as
described in association with the BMD3 device, device 500 includes
a stopgap mechanism. Some embodiments of the BMD3 device have
already described the application of a sensor in the body of the
impaction rod. Device 500 includes sensing system/assembly 505
embedded in device 500, for example proximate rod 110 near distal
end 210, and used to provide valuable feedback information to the
surgeon. Pressure sensor 505 can let the surgeon know when the
pressures seems to have maximized, whether used for the insertion
of an acetabular cup, or any other implant including knee and
shoulder implants and rods used to fix tibia and femur fractures.
When pressure sensor 505 is not showing an advance or increase in
pressure readings and has plateaued, the surgeon may determine it
is time to stop operation/impacting. An indicator, for example an
alarm can go off or a red signal can show when maximal peak forces
are repeatedly achieved. As noted above, the incorporated patents
describe a presence of a pressure sensor in an installation device,
the presence of which was designed as part of a system to
characterize an installation pulse pattern communicated by a pulse
transfer assembly. The disclosure here relates to a pressure sensor
provided not to characterize the installation pulse pattern but to
provide an in situ feedback mechanism to the surgeon as to a status
of the installation, such as to reduce a risk of fracturing the
installation site. Some embodiments may also employ this pressure
sensor for multiple purposes including characterization of an
applied pulse pattern such as, for example, when the device
includes automated control of an impacting engine coupled to the
hammer. Other embodiments of this invention may dispose the sensor
or sensor reading system within a handle or housing of the device
rather than in the central rod or shaft.
FIG. 6 illustrates an alternative device 600 embodiment to the
feedback system of FIG. 5 including a sound sensor 605 to provide
feedback for the embodiments of FIG. 1-5. Surgeons frequently use a
change in pitch (sound) to gauge whether an implant (e.g., the cup)
has "bottomed out" (an evaluation of a "seatedness" of the implant)
and device 600 includes sound sensor 605 either attached or coupled
to rod 110 or otherwise disposed separately in the operating room.
Sound sensor system/assembly 605 may be used in lieu of, or in
addition to, pressure sensor system/assembly 505 illustrated in
FIG. 5.
FIG. 7-FIG. 10 illustrate prosthesis assembly embodiments including
use of variations of the prosthesis installation embodiments of
FIG. 1-FIG. 6, such as may be used to reduce a risk of trunionosis
or for other advantage. FIG. 7 illustrates a modular prosthesis 700
and assembly tool 705. Prosthesis 700 includes a head 710 and a
trunion taper 715 at an end of a stem 720 (e.g., a femoral stem for
supporting a ball head to fit within an acetabular cup used in a
total hip replacement procedure). During the procedure, the surgeon
assembles prosthesis 700 by using tool 705 which may include an
impact rod 725 attached to a head coupler 730. The surgeon uses
tool 705 to drive head 710 onto trunion taper 715 which
conventionally includes a free mallet striking tool 705. Such a
procedure may be prone to the similar problems as installation of a
prosthesis into an implant site, namely application of off-axis
torqueing forces and an uncertainty of applied force and completion
of assembly.
It is believed that even a 0.1 degree mal-alignment on head 710 on
trunion taper 715 may lead to progressive wear and metalosis.
Variations of the embodiments of devices illustrated in FIG. 1-FIG.
6 and its associated content may be developed to help resolve this
problem. In the case of "non-torqueing axiallity" of forces from an
assembly device, a bore of the head may define an axis, the trunion
taper may define an axis, with the assembly device aligning these
axes and then applying its forces in co-axial alignment with these
co-axially aligned axes. Such an embodiment may reduce or eliminate
any force-responsive rotations of the head with respect to the
taper as the head is seated into position by the assembly
device.
FIG. 8 illustrates a femoral head 805, a variation of head 710
illustrated in FIG. 7, to be assembled onto trunion taper 715 that
is coupled to femoral stem 720. A center dot 810 may be placed on
femoral (or humeral) head 805 to be impacted using tool 705.
FIG. 9 illustrates alignment of an installation device 900, a
variation of any of devices 100-600, with femoral head 805 for
properly aligned impaction onto trunion taper 715, such as an
embodiment of FIG. 1-FIG. 6 adapted for this application. Such
adaptation may include, for example, an axial channel 910 to view
dot 810 through a slot 915, and align force transference, prior to
operation of hammer 105. A sledgehammer 920 is coupled to a cock-up
spring 925.
Dot 810 can be aligned with an impactor/device/gun. Once axial
alignment, such as through the sight channel, has been confirmed, a
sledgehammer, a cockup gun, or other similar device can bang the
impactor onto femoral (humeral) head 805 to impact it on trunion
taper 715. The co-axiality of the head and the device can be
confirmed visually (for example, through a hollow cylinder that
comprises a center shaft of the device) or with a variety of
electronic and laser methods.
FIG. 10 illustrates use of a modified vibratory system 1000, a
variation of installation device 900 for assembly of the modular
prosthesis illustrated in FIG. 7. Alternatively to device 900, a
variation of the BMD3 device can be used to insert the femoral and
humeral heads 710 onto trunion taper 715. For example, a version of
the BMD3 device where femoral head 710 is grasped by a "vibrating
gun" and introduced methodically and incrementally onto trunion
taper 715. Since there are no large forces being applied to the
head/trunion junction, there is essentially no possibility, or a
reduced possibility, of head 710 seating onto trunion taper 715 in
a misaligned fashion. It would be possible to use the same
technique of marking the center of head 710 and lining it up with
trunion taper 715 and device axially before operating the
device.
FIG. 11-FIG. 12 illustrate an improvement to site 1100 preparation
for an installation of a prosthesis 1105. FIG. 11 illustrates an
environment 1100 in which prosthesis 1105 is installed highlighting
a problem with site preparation for a prosthesis installation
procedure having variable density bone (line thickness/separation
distance reflecting variable bone density) of acetabulum 1110.
There is a secondary problem with the process of acetabular
preparation and implantation that leads to cup mal-alignment.
Currently, during the process of acetabular reaming, surgeons make
several assumptions. One common assumption is that the reamer is
fully seated in a cavity and surrounded on all sides by bone.
Another common assumption is that the bone that is being reamed is
uniform in density. Imagine a carpenter that is preparing to cut a
piece of wood with a saw. Now imagine that parts of this piece of
wood are embedded with cement and some parts of the piece of wood
are hollow and filled with air. The carpenter's saw will not
produce a precise cut on this object. Some parts are easy to cut
and some parts are harder to cut. The saw blades skives and bends
in undesirable ways. A similar phenomenon happens in acetabular
preparation with a reamer and when performing the cuts for knee
replacement with a saw. With respect to the acetabulum, the side of
the cavity that is incomplete (side of the reamer that is
uncovered) will offer less resistance to the reamer and therefor
the reamer preferentially reams towards the direction of the
uncovering. Second, the reamer cuts the soft bone much more easily
than the dense and sclerotic bone, so the reamer moves away from
the sclerotic bone and moves toward the soft bone. From a machining
perspective, the reaming and preparation of the acetabulum may not
be concentric or precise. This maybe a significant factor in the
surgeon's inability to impact the cup in the desired location
FIG. 12 illustrates an alignment system 1200 for preparation and
installation of a prosthesis to help address/minimize this effect.
A first step that can be taken is to include directionality into
the process of reaming at the outset, and not just at the last step
during impaction. Current technique allows the surgeon to ream the
cup haphazardly moving the reamer handle in all directions, being
ignorantly unaware that he is actually creating a preference for
the sinking path of the acetabular implant. Ultimately the
direction in which the surgeon reams may in fact be determining the
position/path of the final implant. The surgeon then impacts the
cup using the traditional A-frame or any of the currently used
intra-operative measurement techniques such as navigation or
fluoroscopy. These methods provide information about the position
of the cup either as it is being implanted or after the
implantation has occurred. None of these techniques predetermine
the cup's path or function to guide the cup in the correct
path.
Proposed is a method and a technique to eliminate/reduce this
problem. Before the surgeon begins to ream the acetabulum, the
reamer handle should be held, with an A-frame attached, in such a
way to contemplate the final position of the reamer and hence the
implant, (e.g., hold the reamer in 40 degree abduction and 20
degree anteversion reaming is started). This step could also be
accomplished with navigation or fluoroscopy. The surgeon could, for
example, immediately mark this position on a screen or the wall in
the operating room as described below and as illustrated in FIG.
12. After the anticipated position of the reamer is marked, the
surgeon can do whatever aspect of reaming that needs to be done.
For example the first reaming usually requires medialization in
which the reamer is directed quite vertically to ream in to the
pulvinar. Typically three or four reamings are done. First, the
acetabular cavity is medialized. The other reamings function to get
to the subchondral bone in the periphery of the acetabulum. One
solution may be that after each reaming, the reamer handle be held
in the final anticipated position of the implant. In some cases it
may be difficult to have an A-frame attached to every reamer and to
estimate the same position of the reamer in the operating space
accurately with the A-frame.
An alternative to that is also proposed to address this process.
For example, at a proximal end of the reamer shaft handle will be
placed a first reference system 1205, for example a laser pointer.
This laser pointer 1205 will project a spot 1210 either on a wall
or on a screen 1215, a known distance from the operating room
table. That spot 1210 on wall 1215 (or on the screen) is then
marked with another reference system 1220, for example a second
independent laser pointer that sits on a steady stand in the
operating room. Thereafter manipulating the shaft handle so that
the first reference system has the desired relationship, example
co-aligned, with the second reference system, the surgeon knows
that the device attached to the handle has the desired orientation.
So when the first reamer is held in the anticipated and desired
final alignment of the implant (e.g., 40 degree abduction, 20
degree anteversion for many preferred installation angles of an
acetabular cup), the laser pointer at the proximal end of the
reamer handle projects a spot on the wall or screen. That spot is
marked with the second stationary laser, and held for the duration
of the case. All subsequent reamings will therefore not require an
A-frame to get a sense of the proper alignment and direction of the
reamer. The surgeon assures that no matter how he moves the reamer
handle in the process of reaming of the acetabulum, that the
reaming finishes with the reamer handle (laser pointer) pointing to
the spot on the wall/screen. In this manner, directionality is
assured during the reaming process. In this way the sinking path of
the actual implant is somewhat predetermined. And no matter what
final intra-operative monitoring technique is used (A-frame, C-Arm,
Navigation) that the cup will likely seat/sink more closely to the
desired final position.
FIG. 13 illustrates modified surgical devices 1300 incorporating
vibratory energy as at least an aid to mechanical preparation. Also
proposed herein is another concept to address a problem associated
with non-concentric reaming of the acetabulum caused by variable
densities of the bone and the uncovering of the reamer. Imagine the
same carpenter has to cut through a construct that is made out of
wood, air, and cement. The carpenter does not know anything about
the variable densities of this construct. There are two different
saws available: one that cuts effectively through wood only, and
ineffectively through the cement. Also available is a second saw
that cuts just as effectively through cement as wood. Which of
these saws would improve a chance of producing a more precise cut?
Proposed is a mixing of ultrasonic energy with the standard
oscillating saw and the standard reamer. In effect any oscillating
equipment used in orthopedics, including the saw, reamer, drill,
and the like may be made more precise in its ability to cut and
prepare bone with the addition of ultrasonic energy. This may feel
dangerous and counterintuitive to some, however, the surgeon
typically applies a moderate amount of manual pressure to the saw
and reamers, without being aware, which occasionally causes
tremendous skiving, bending and eccentric reaming. An instrument
that does not requires the surgeon's manual force maybe
significantly safer and as well as more precise and effective.
A further option includes disposition of a sensor in the shaft of
the ultrasonic reamers and saws so that the surgeon can ascertain
when hard versus soft bone is being cut, adding a measure of safety
by providing a visual numerical feedback as to the amount of
pressure being utilized. This improvement (the ability to cut hard
and soft bone with equal efficacy) will have tremendous
implications in orthopedic surgery. When the acetabular cavity is
prepared more precisely, with significantly lower tolerances,
especially when directionality is observed, the acetabular implant
(cup) may more easily follow the intended sinking path.
Other applications of this concept could be very useful. Pressfit
and ingrowth fixation in total knee replacements in particular (as
well as ankle, shoulder and other joints to a lesser degree) are
fraught with problems, particularly that of inconsistent bony
ingrowth and fixation. The fact that a surgeon is unable to obtain
precise cuts on the bone may be a significant factor in why the
bone ingrowth technology has not gotten off the ground in joints
other than the hip. The problem is typically blamed on the surgeon
and his less than perfect hands. The experienced surgeon boasts
that only he should be doing this operation (i.e.: non-cemented
total knee replacement). This concept (a more precise saw that cuts
hard and soft bone equally allowing lower tolerances) has huge
potential in orthopedics, in that it can lead to elimination of the
use of cement in orthopedic surgery altogether. This can spark off
the growth and use of bone ingrowth technology in all aspects of
joint replacement surgery which can lead to tremendous time saving
in the operating room and better results for the patients.
FIG. 14 illustrates a BMD 1400 having bidirectional longitudinal
motion; and FIG. 15 illustrates a BMD 1500 having bidirectional
rotational motion. In previous discussions of BMD3 vibratory and
operational devices, specific directionality controls of the
movement were not addressed as described herein. Many vibratory
systems are "driven" in one-direction based upon a particular
application. Disclosed herein are devices that have intentionally
designed and allow for, based upon application, for
unidirectionality in applied force by an oscillatory engine. For
procedures and processes relating to preparing an installation
site, installing a prosthesis, and revising/removing an installed
prosthesis, there may be advantages in different directionalities
in different contexts. Rather than having three different tools,
the present disclosure contemplates a tool having multiple
selectable directionalities allowing it to be used in different
procedures.
Also disclosed is a new type of cavity formation tool (for hip
replacement in preparation of the pelvic bone) that may
advantageously employ bidirectional vibratory motion: a broach for
the acetabulum cavity preparation.
BMD3 bidirectional vibratory tool: The BMD3 vibratory tool was
initially created and envisioned for vibratory insertion of
prosthesis into bone. During the experimentation of BMD3 vibratory
tool we discovered that vibratory energy can be unidirectional in
forward and backward directions or it can be bidirectional. We have
described the effectiveness and use of unidirectional forward
vibrating BMD3 tool for insertion of a prosthesis (in particular
acetabular prosthesis) into bone. We now propose use of
bidirectional BMD3 vibratory tool for the purpose of preparing
bone, and in particular the acetabular cavity.
BMD3 bidirectional vibratory tool for preparation of bone, and in
particular the acetabular cavity: The use of a Acetabular Broach: a
new idea. BMD3 bi-directional vibratory tool can be used for
preparation of bone (any cavity of bone that needs to be prepared
for application of a prosthesis, but especially the acetabulum, as
well as the proximal femur, proximal tibia, proximal humerus, and
any other long bone in the body that receives a prosthesis). With
regards to the acetabulum, unlike the other bones discussed above,
this structure has never before been prepared with a broach, but
rather always prepared with a hemispherical "cheese grater type"
reamers that rotates in one direction (forward). We are proposing
that the acetabulum be prepared with a broach using one of the two
degrees of freedom for oscillation
(1. Longitudinal and 2. rotational), utilizing a bidirectional BMD
vibratory tool. The outer surface of this broach will very closely
resemble the rough surface of the prosthesis, with high coefficient
of static friction. We have seen this method in action in our
experiments, particularly at higher frequencies of around 300
hertz, and believe that this method of acetabular preparation will
provide a cut surface that is much more precise and conferring the
ability to produce lower tolerances. This method may also allow
preparation of acetabular cavity in "half" sizes. Currently the
cavity is reamed in 1 mm intervals. It may be much easier to
prepare the acetabulum with 1/2 mm interval broaches than 1/2 mm
reamers. Half size broaching may dramatically improve the ability
of the surgeon to cut and prepare the acetabular precisely and at
lower tolerances.
For purposes of review we recall the equation FR=KxUs. Where x is
represents the amount of under reaming and the shape of the cup
being inserted.
X is controlled by the amount of under or over reaming of the
acetabulum. In the past when the surfaces of the cup were not as
rough (lower coefficient of static friction, i.e. Zimmer Fiber
Metal cup), surgeons used to under ream by 2 mm. Now most companies
recommend under reaming by 1 mm, since the surfaces of most cups
are much more rough with better porosity characteristics that allow
better and quicker bony ingrowth. Sometimes when the surgeon has
difficulty seating the cup, he/she reams line to line, and
describes this action as "touching up the rim". This action
however, many times, eliminates the compressive quality of the
acetabulum by decreasing the value of x towards zero. This issue
brings attention to the problem that we have described which is
that the surgeon does not have anything but a most basic
understanding of the spring like qualities of bone. If he/she is
can understand the basic science involved in this system, he can
then use the proper tools to appropriately fine tune the pelvis for
a good press fit fixation, without fear of under seating or
fracture. There is a huge market need for better tools to prepare
(fine tune) the acetabulum, for good press fit fixation.
Current techniques utilize `cheese grater type` hemispherical
reamers to prepare the bed of the acetabulum. As discussed in our
BMD4 paper the quality of acetabular bone can be drastically
different between patients and even within the same patient,
particularly at different locations around the acetabular fossa.
Some parts of the bone are soft, and some are hard. Current cheese
grater hemispherical reamers come in 1 mm intervals. This creates
two specific problems: 1. The current acetabular reamers in 1 mm
intervals for preparation of the acetabular bone do not provide the
ability to precisely machine the acetabulum, and obtain lower
tolerances, and therefore proper tuning of the pelvic bone. 2. No
method exists to cut hard and soft bone with the same level of
effectiveness, i.e.: hard bone always pushes the reamers towards
the soft bone which ends up being chewed up more, and in that
sense, a perfect hemisphere is not created with current cheese
grater reaming techniques. We therefore are proposing two distinct
and separate solutions which we believe can remedy this problem of
poor quality acetabular preparation.
1. The creation of half reamers. The production and use of half
reamers gives the surgeon the ability to ream up or down by half
millimeters. Which gives him/her the ability to fine tune x more
precisely, and therefore FR more precisely. This basically gives
the surgeon a better set of tuning forks to obtain better tension
for the acetabulum and utilize its viscoelastic properties to
his/her advantage to obtain a better press fit fixation.
2. Ultrasonic assisted reaming or broaching: Lastly, we believe
that there is some room for creating a better cutting tool by
adding ultrasonic energy to either the acetabular broach described
above or the acetabular half reamers described above to create an
ultrasonic assisted reaming or broaching of the acetabulum for
obtaining a more precise cut and at a lower tolerance. We believe
this is a new and novel idea that can be considered for preparation
of the acetabulum for obtaining better tension of the pelvis for
application of an acetabular prosthesis.
The system and methods above has been described in general terms as
an aid to understanding details of preferred embodiments of the
present invention. In the description herein, numerous specific
details are provided, such as examples of components and/or
methods, to provide a thorough understanding of embodiments of the
present invention. Some features and benefits of the present
invention are realized in such modes and are not required in every
case. One skilled in the relevant art will recognize, however, that
an embodiment of the invention can be practiced without one or more
of the specific details, or with other apparatus, systems,
assemblies, methods, components, materials, parts, and/or the like.
In other instances, well-known structures, materials, or operations
are not specifically shown or described in detail to avoid
obscuring aspects of embodiments of the present invention.
Reference throughout this specification to "one embodiment", "an
embodiment", or "a specific embodiment" means that a particular
feature, structure, or characteristic described in connection with
the embodiment is included in at least one embodiment of the
present invention and not necessarily in all embodiments. Thus,
respective appearances of the phrases "in one embodiment", "in an
embodiment", or "in a specific embodiment" in various places
throughout this specification are not necessarily referring to the
same embodiment. Furthermore, the particular features, structures,
or characteristics of any specific embodiment of the present
invention may be combined in any suitable manner with one or more
other embodiments. It is to be understood that other variations and
modifications of the embodiments of the present invention described
and illustrated herein are possible in light of the teachings
herein and are to be considered as part of the spirit and scope of
the present invention.
It will also be appreciated that one or more of the elements
depicted in the drawings/figures can also be implemented in a more
separated or integrated manner, or even removed or rendered as
inoperable in certain cases, as is useful in accordance with a
particular application.
Additionally, any signal arrows in the drawings/Figures should be
considered only as exemplary, and not limiting, unless otherwise
specifically noted. Combinations of components or steps will also
be considered as being noted, where terminology is foreseen as
rendering the ability to separate or combine is unclear.
The foregoing description of illustrated embodiments of the present
invention, including what is described in the Abstract, is not
intended to be exhaustive or to limit the invention to the precise
forms disclosed herein. While specific embodiments of, and examples
for, the invention are described herein for illustrative purposes
only, various equivalent modifications are possible within the
spirit and scope of the present invention, as those skilled in the
relevant art will recognize and appreciate. As indicated, these
modifications may be made to the present invention in light of the
foregoing description of illustrated embodiments of the present
invention and are to be included within the spirit and scope of the
present invention.
Thus, while the present invention has been described herein with
reference to particular embodiments thereof, a latitude of
modification, various changes and substitutions are intended in the
foregoing disclosures, and it will be appreciated that in some
instances some features of embodiments of the invention will be
employed without a corresponding use of other features without
departing from the scope and spirit of the invention as set forth.
Therefore, many modifications may be made to adapt a particular
situation or material to the essential scope and spirit of the
present invention. It is intended that the invention not be limited
to the particular terms used in following claims and/or to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
any and all embodiments and equivalents falling within the scope of
the appended claims. Thus, the scope of the invention is to be
determined solely by the appended claims.
* * * * *